The invention relates generally to devices for positioning the upper extremity during a computerized axial tomography (CAT) scan, and more particularly to a device for accurately positioning of the distal radioulnar joint for examination.
The prior art is deficient in consistent objective criteria and methods for evaluating subluxation in the distal radioulnar joint (DRUJ). Typical methods for evaluating subluxation or translation motion in the DRUJ includes computerized axial tomography (CAT) analysis and x-ray radiography. The CAT scan is a preferable method for the evaluation of the DRUJ by providing a coronal cross-sectional image of the radius and ulna. Moreover, radiographs can be misleading because a slight rotational change (10.degree.) in position of the joint may appear as a subluxation, instability or dislocation in the joint and therefore may not allow satisfactory visualization of the joint.
The invention solves or substantially reduces in importance shortcomings in prior radiographic examinations by providing a platform for positioning and retaining the forearm of a subject for CAT scan of the DRUJ. The device comprises a base on which two blocks are mounted and support a plurality of adjustable positioning posts for holding the radius in position and applying a selected degree of stress on the ulna. The invention allows stress to be applied to the radius and ulna to assess stability in the DRUJ.
It is therefore a principal object of the invention to provide a device for positioning the arm for CAT scan.
It is another object of the invention to provide a device for positioning the distal radioulnar joint for CAT scan or x-ray.
These and other objects of the invention will become apparent as a detailed description of representative embodiments proceeds.